美洲黑杨小孢子母细胞减数分裂进程与花芽及 花药外观形态相关性研究

以美洲黑杨的雄花枝为材料,采用卡宝品红压片法,观察花粉母细胞减数分裂进程与花芽及花药外观形态的关系, 为美洲黑杨2n配子的诱导奠定基础。结果表明:美洲黑杨雄花花序开始露出芽鳞之前,小孢子母细胞减数分裂已经结束; 花芽顶端及侧面的芽鳞开始松动时,在同一花序中可以观察到从小孢子母细胞到花粉粒的所有减数分裂阶段,此时是诱导2n配子的最佳时期; 美洲黑杨花药长度与减数分裂阶段密切相关,长约0.5 mm的花药处于减数分裂的小孢子母细胞阶段, 长约1.0 mm的花药处于减数分裂的细线期、粗线期、中期Ⅰ、末期Ⅰ及二分体阶段,长约1.5 mm的花药处于减数分裂的四分体时期,长约2.0 mm的花药已处于花粉粒阶段; 同一花枝上的不同花芽及同一花序中不同小花的发育不同步,但同一小花中的不同花药发育基本一致。美洲黑杨减数分裂过程中染色体行为正常,是分子细胞遗传学研究的良好实验材料。

Relationship between the meiosis processes of microsporocytes and morphology of male flower buds and anthers in Populus deltoides Marsh

With carbol fuchsin staining, we studied the relationship between the meiosis processes of microsporocytes and the morphology of male flower buds and anthers in Populus deltoides Marsh, laying the foundations for inducing 2n gametes in this species. The results were as follows: The meiosis ended before the catkin came out of the bud scale. When the bud scale from the top or lateral of the flower bud began to loosen, all the meiosis processes were found from the same flower bud, and this time was optimum for inducing 2n gametes. The length of anthers in P. deltoides Marsh and the stages of meiosis were closely related. The 0.5 mm-long anther was at the stage of microsporocytes, the 1.0 mm-long anther was at the stage of leptotene, pachytene, metaphase Ⅰ, telophase Ⅰ and dyad, the 1.5 mm-long anther was at the stage of tetrad, the 2.0 mm-long anther was at the stage of pollen. Different flower buds in one flowering branch or different florets in one flower bud showed non-synchronization in the meiosis processes of microsporocytes, but different anthers in one floret showed synchronization in the processes. The behavior of chromosomes was standard during the meiosis processes of microsporocytes in P. deltoides Marsh. It could make this species a good experimental material for molecular cytogenetic study.